h- jqrgensen



Feb. 11, 1947. C, H JORGENSEN 22,840

AUTOMATIC CHOKE MEGHANISM AND CHOKE VALVE Original Filed Oct. 17, 1934 2 Sheets-Sheet l ATTORNEYS Feb- 11, 1947- c. H. JORGENSEN AUTOMATIC CHOKE MECHANISM AND CHOKE VALVE Original Filed Oct. 1'7, 1934 2 Sheets-SheeiI 2 INVENTQR fw CA'TTOIRNEYS da Reissued Feb. l1, 1947 .AUTOMATIC CHOKE MEHANISM AND CHOKE VALVE Clarence H. Jorgensen, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Original No. 2,327,903. dated August 24, 1943, Sc-

rial No. 748,605. October 17, 1934. Application for reissue ctober 1l, 1943, Serial No. 505,861

(ci. zei-ss) 21 Claims.

'rms invention relates to an automatieehoke mechanism for automatically controllingV the choke or air intake valve of a charge forming device for an internal combustion engine to facil-` itate starting of the engine and to a novel form of choke valve.

`It is an object of the present invention to provide an automatic choke mechanism in which the choke valve is controlled by the joint action of engine suction and thermally responsive means which is so designed that the valve is positioned bysaid thermally responsive means to increase the proportion of fuel in the combustible mixture inversely in accordance with the temperature adjacent said thermally responsive means and is operable by engine suction to decrease the proportion of fuel in the combustible mixture upon increase of suction effective on said valve.

It is a further object of the invention toprovide a choke valve having a part adapted to completely close the air intake passage when in closed position and may be moved to position to fully open the intake passage. and is provided with a second part which is movable independently of the first mentioned part, but is resiliently held in position to restrict the air intake passage when said nrst mentioned part is in partly opened position.

It is a further object of the invention to provide a choke valve constructed as set forth in which the second mentioned part is movable by the blast ofthe entering air when the first mentioned part is in partly opened position and to providemeans to positively move the said second mentioned part to a position where it does not restrict the intake e at all when the nrst mentioned part of said valve is in fully open position.

It is a still further object of the invention to provide a choke valve'of the type described and means for positively positioning the first mentioned part of said valve by means of a thermally responsive device and by means of engine suction in the manner previously set forth.

Further objects and advantages of the present invention will be apparent from the following 2 Figs. 3. 4 and 5' are detail sections through the air intake of the carburetor showing the choke valve in different positions.

Fig. 6 is a section on the line 5 6 of Fig. l.

Fig. 7 is a detail section on line 1-1 of Fig. 4.

Referring to the drawings, the intake manifold is indicated at ill and is provided with a hot spot I2,V to which is secured a downdraft carburetor unit Il. that illustrated in the drawings being the well known Carter carburetor which need not be described in detail. The carburetor unit is provided with a main housing II in which the main intake passage is located and received in the upper end oi' this housing is an air intake coupling Il in which the choke valve hereinafter described is positioned. Shown in Fig. 2 is an operating arm secured -tc the end of a .spindle 22 on which is mounted a throttle valve (not shown) of ordinary construction which m regulates the flow of combustible mixture to the engine in the usual manner.

Jcurnalled in the intake coupling Il is a spindle 24 to the flat portions of which adjacent the ends is secured a choke valve 2l which is of such size description. reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings: Fig. 1 is a side elevation of an intake manifold y and carburetor unit in which a choke valve and as to completely close the` intake passage as shown in Fig. (i. Associated with the valve 2B is a half valve 28 which is adapted when the choke valve 2l is in the position shown in Fig. 4 to be against a. shoulder Il, formed on the inner wall ofthe air intake coupling. by a spring I2, one end of which is attached to a pin I4 extending from the half valve and at its other end to a similar pin 30 projecting from the main choke valve 2B.

The main valve 20 is rigidly secured to the spindle .24 by screws while the half valve 28 is rotatable with respect to said spindle. To this end the ,main valve 26 is provided with an opening Il at the middle part thereof and through this opening an extending tongue 40 of the half valve is projected being bent into cylindrical form as shown in the drawings so that it is rotatably `lournalled on a cylindrical portion of the spindle 2| formed at the middle part thereof and nts sumciently loosely to rotate freely thereon.

The hub portion of the half valve has a raised portion at the center which may be formed by brazing a separate piece to the hub or in any other suitable way and is provided with a series of orifices I2 which cooperate with gear teeth u formed on the end of an arm Il pivotally mounted by a pint8 on an arm Il secured to the valve It by pins 52.

The operation o! this. valve mechanism is subposition.thepartsareinthepositlonshownin.

When the mainvalve 2l ismcvedto partly open position. by means to be presently described, the parts assume the position shown in Fig. 5. It will be noted that in this position of the main vulve the half valve may lay behind the main valve to restrict the intake passage to a greater degree thanthemainvalveassnowninsaidlig. 6.0i' may move to a position to restrict saidpassage to the same degree as does the main valve, the position of the nali valve being dependenton the air pressure effective thereon. its opening movement being opposed by the action of the spring $2.

When the valve 26 is moved to full open position.asshowninFig.3.thearm4iismove d into engagement with the inner surface of the air intake coupling with the result that such arm is rotated on its pivot in a counter-clockwise direction and through engagement of teeth 44 with orifices 42, rotates the half valve 2l -to the position shown in Fig. 3, regardless of what degree of suction may be effective on such valve.

It should lbe noted that the spindle 24 is mounted somewhat to one side of the intake passage so that the valve 2l is somewhat on center.V

Therefore, the air pressure effective on the valve itself tends to move it toward open position as well as the suction operated means which has been previously referred to and will be described in detail later.

The position of the main valve is primarily determined by the automatic choke mechanism previously referred to, and to this end an operating arm I4 is secured to one end ofthe spindle 24, said arm being pivotally connected to a link which at its opposite end is pivotally connected to an operating arm I8 secured in any desirable way to one end of a shaft 8U suitably iournalled in a housing B2. The housing 02 is Provided witha detachable bottom 8l secured in position by tangs 82a and secured to a plate G4 adapted to be secured to the previously menconduitllwhich. atene end communicates with a central bore Il formed 'within the nipple 'Il and communicatingat one end-1 with the interior of the bellows.' nv-adjustable tapered metering valve Il is received within' the bore Il and may be adlusted to determine the rate at tioned hot spotfby machine screws 86 or in any other desirable manner. A gasket Bl is provided between the plate and the manifold, above the housing l2 and secured thereto in any desirable way is a cylindrical housing 38 in which is received a Sylphon bellows 10. the function of which will be more fully described later.

A thermostat 12 is provided which is connected at one end to the shaft 80 as shown in Fig. 6 and at its other end is connected to pin 14 projecting from a connecting link Il which is pivotally connected at its upper end to a pin 'Il carried by the two depending arms of a yoke I0 secured to the solid head 82 which forms the bottom of the Sylphon bellows 10, the yoke extending downwardly through an opening B4 inV the top of the housing B2.

A solid head 88 somewhat similar to the head s2 is provided at the upper end of the Bylphon bellows and this upper head is prevented from moving when a 'partial vacuum is produced within the bellows because it is clamped by anges projecting from the nipple 88. to the top lll of the cylindrical housing B8. Therefore, when a partial vacuum is created within the bellows by the communication of engine suction thereto, the lower head l2 of the bellows is pulled .upwardly and this motion is opposed by the coil spring 92 which is received within the bellows.

To communicate the engine suction to the lnterior of the bellows there is provided a suction which air is exhausted from the bellows and therefore. can determine the rate at which the head l2 oi' the bellows is pulled upwardly. The suction conduit at the opposite end extends through the plate I4 and registers with a sultable suction passage (not shown) in the wall of the manifold which communicates with the interior thereof.

Secured at the end of shaft l0 opposite to that on which the arm 68 is secured and within Il of housing l2 to communicate atmospheric' pressure to the bottom head l2 of the Sylphon to force the head upwardly when a subatmospheric pressure is created within the bellows.

There may be formed in the lower end of the link 'IB an opening IDI to which a manual operating connection for the choke may be connected and an opening |02 may be Provided inl the bottom plate Il for such operating connection to extend through if desired. f

Means are provided to adiustably determine the position of the throttle valve at idling in accordance with the position of the choke. For this purpose a link lill has a bent over.upper end which extends through a suitable hole in the operating arm. At its lower end this link projects through the horizontal portion of an angle bar ||2 which has a vertical portion elidable in any formV of suitable guiding means. The guiding means may be a track formed in the carburetor housing or may be a separate bracket Ii4 secured by a screw or other suitable means to the carburetor housing. The vertical portion of the element ||2 slides in such guide means. The link is provided with an adjustable collar lil above the horizontal portion of the bar ||2 and received between thisbar and a washer Ill at the lower end of the link is a spring |2II which normally retains the bar I i2 in.` contact with said shoulder as shown in Fig. 2. The lower end of the angle bar is tapered as indicated at l2 and this tapered end cooperates with a screw |24 carried by the `throttle operating arm 2li.

The operation of this idle control mechanism is as follows. The link lill moves with the main portion of the choke valve and its position at idling is determined by the thermostat. If the engine is cold it is held in its lower position and the collar III moves the angle bar I|2 downwardly so that some part of its tapered lower end is opposite the screw |24 which will determine the closed or idling position of the throttle. If it is cold. a thicker portion of the tapered end of angle bar I|2 is opposite screw |24 than if the temperamre is higher because link Il! is in lower position. 'Ihis will result in a wider open lthrottle and faster idling than when the temth housing 02 is an operating arm lill which] sasso fective to hold the valve 26 in closed position. such position being determined by the thermostat. As the engine is turned over by the starting motor, suction is communicated to the bellows and ii' the engine fails to start for any appreciable time, the suction in the bellows will build up suiliciently to open the valve 26 to admit enough air to prevent flooding.

When the engine starts to run, the suction eilective both on the bellows and on the valve 2l increases and pulls the valve 26 open to a greater degree. At such time the spring held half valve 28 tends to lag behind-the main valve owing to the spring tension which has to be overcome and prevents suiilcient air entering to lean the mixture to a degree which will stall the engine or cause it to miss.

If the throttle is opened to accelerate during the warm up period, the suction eilective on the bellows falls while the suction directly effective on the valve itself increases with the result that the valve is moved toward open position notwithstanding the drop in suction in the bellows. Under these conditions the half valve 28` also tends to restrict the passage to a greater degree than the valve 26 and so is eective to prevent too much leaning of the mixture during acceleration. i

secondary part movable independently of and,

relatively to the said main part, both parts of said valve being movableby the eiect of air Dressure, and resilient means controlling the movement of said secondary part relative to the main part so that the secondary Vpart tends tolag behind the main part as the valveis opened for the purpose of restricting the ow of air into the intake passage to a greater degree than the main part oi.' such valve.

3. A choke valve such as defined in claim 2 in combination with thermally responsive means connected directly with said main part of the valve for-operating said valve. y

4. A choke valve such as-dei'lned in claim 2 in combination with thermally responsive means andl means operable by engine suction connected directlyv with said main part of the valve for operating said valve.

5. VA choke valve for carburetors having an air intake passage, comprising a main part and a secondary part, and so constructed that said main part constitutes the principal restriction in said Afterthe engine has warmed up suiiiciently, y

the thermostat operates to move the parts to the position shown in Fig. 3 in which position the half valve has no restricting eiect on the intake passage whatever.

With a spring 32 of proper tension the auxiliary or half valve steps up the fuel proportion in the mixture just enough to give smooth idling and part throttle operation, as Well as proper acceleration peri'ormance during the warm up period. In plain tube carburetors there is a noticeable nat spot `lust at the point of transfer of fuel ilow from the idle to main fuel jet, but this form of choke valve is effective to eliminate this "flat spot substantially entirely.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. Y

What is claimed is as follows:

l. In a carburetor for internal combustion'engines having an air inlet and a vchoke valve assembly for controlling said air inlet which is automaticaily movable to diierent positions to variably restrict the iiow of air into the carburetor to facilitate starting and is adapted to be-moved to a non-restricting position when the engine is operating under normal conditions, said choke valve assembly comprising a larger main part and a smaller secondary part, said main part being constructed to constitute the greatest restriction to ow of air to the intake passage when the valve is in closed position and means for causing said secondary part to restrict the flow oi' air into the said passage to a greater degree than the main part of said valve when the valve is partly open.

2. In a carburetor for internal combustion engines having an air inlet and an unbalanced choke valve assembly forl controlling said air inlet which is automatically movable to different positions to variably restrict the iiow of air into the carburetor to facilitate starting and is adapted to be moved to a non-restricting position when the engine is operating under normal conditions, said choke valve assembly being operable by air pressure thereon and comprising a main part and a trol the flow of air therethrough, thermally re.

air intake passage under certain operating conditions while the. secondary valve constitutes the greater restriction'under other operating conditions, a throttle, and means operable by said main part of the choke valve to limit the closing movement of the throttle valve so as to determine the idling position of the throttle in accordance with the position of said main part of the chate valve.

6. In a carburetor having an air intake passage, a choke valve in saidV passage and operable to consponsive means controlling the opening of said choke, a throttle valve, a movable throttle stop device, mechanism operable by the choke valve for positioning said stop device, said mechanism being so constructed that said device is moved to a fast idle position when said choke is closed, to prevent full closing movement of said throttle valve and to permit faster than normal idling ci the engine, and is movable to an. inoperative posi-` tion during opening movement of said choke valve and substantially before said choke valve is i'ully opened, said mechanism being constructed to permit at least partial opening of saidchoke valve without moving said stop device from said fast idle position.

7. In a carburetor having an air intake passage,

a choke valve in said passage and operable to control the now of air therethrough, means for positionlng said choke valve in accordance with engine temperature and suction, a throttle valve, a movable throttle stop device, mechanism operable by the choke valve for positioning said stop device, said mechanism being so constructed that said device is moved to a fast idle position when said choke is closed, to prevent full closing movement oi' said throttle valve and to permit faster than normal idling of the engine, and is movable to an inoperative position during opening movement of said choke valve and substantially before said choke valve is fully opened, said mechanism being constructed to permit at least partial opening of said choke valve without moving said stop device from said fast idle position.

8. In a carburetor for internal combustion engines having an intake passage, a choke valve controlling the ilow of air therethrough, said valve comprising main and secondary portions, operating means for said valve, said main portion providing the principal restriction to the now of enward a position to provide a minimum restriction on the ow oi' air entering the carburetor andV means tending to maintain the secondary portion of said valve in nxed position as the main portion oi the valve is moved so that the secondary portion of the valve can restrict the iiow oi air to a greater degree than the main portion ot such valve as the latter moves toward the position where it provides a minimum restriction to the ilow of entering air.

9. In a carburetor for internal combustion engines having an intake passage, a choke valve controlling the ilow of air therethrough, said valve comprising main and secondary portions, operating means for said valve, said'main portion providing the principal restriction to the ow of entering air when the valve is closed, means for moving the said'mainrportion of said valve toward a position to provide a minimum restriction on the flow of air entering the carburetor and a resilient member tending to maintain the secondary portion oi' said valve in position to materially restrict the ilow of entering air as the main portion oi' the valve is so moved.

10. In a carburetork for internal combustion engines having an intake passage, a choke valve controlling the ow of air therethrough, said valve comprising main and secondary portions, operating means for said valve, said main portion providing the principal restriction to the ilow of entering air when the valve is closed, means for moving said valve toward a position to provide a minimum restriction to the ow lof air entering the intake passage, said means having direct connection with the main portion oi said valve and a lost motion connection with the secondary portion oi' said valve whereby said main portion of the valve can be moved toward open position without corresponding movement of the secondary portion, and resilient means tending to hold said secondary portion of said valve in posi-tion to provide maximum restriction to the air ilow as the main portion oi' said valve is moved toward ay position to provide minimum restriction to the ow oi air.

11. A choke valve construction ior carburetors having an intake passage, said valve comprising main and secondary portions, said main portion providing the principal restriction to the ilow of entering air when the valve is closed, means for moving said valve toward a position to provide a minimum restriction to the ilow of air entering the intake passage, said means having direct connection with the main portion ofrsald valve and a lost motion connection with the secondary portion of said valve whereby said main portion oi! the valve can be moved toward open position without corresponding movement of the secondary portion, and resilient means tending to hold said secondary portion of said valve in position to provide maximum restriction to the air ow as the main portion of said valve is moved toward a p0- sition to provide minimum restriction to the ow of air, and means operable when the main portion of said valve reaches its full open or minimum ilow restricting position to move said secondary portion of said valve to its full open position.

12. A chokevalve construction for carburetors having an intake passage, said valve comprising main and secondary portions, said main portion providing the principal restriction to the ilow of entering air when the valve is closed, means tor moving said valve toward a position to provide a I minimum restriction to the iiow o! ail-entering 8 the intake passage, said means having direct connection with the main portion of said valve and a. lost motion connection with the secondary Dortion oi.' said valve wherebysaid main portion of the valve can be moved toward open position without corresponding movement of the secondary portion, and resilient means tending to hold said secondary portion of said valve in position to provide maximum restriction to the air tlow as the main portion of said valve is moved inward a position to provide minimum restriction to the dow oi' air, and a member carried by the valve assembly and operable when the main portion ot said valve'reaches its full open or minimum ilow restricting position to move said secondary portion of said valve to its full open position, said member being operated by engagement thereof with the wall of -the intake passage when the main por.. tion of the valve reaches full open position.

13. In a carburetor having an air intake passage, a choke valve comprising a main part and Y a secondary part, and so constructed that said main part constitutes the principal restriction in the air intake passage under certain operating conditions, while the secondary part of said valve constitutes the greater restriction to the admission of air into said intake passage under other operating conditions, thermally responsive means for positioning the choke valve to increase the fuel proportion in the mixture inversely as to the temperature and means operable by engine suction to move the valve to decrease the proportion of fuel in the mixture. l I

- 14. In a carburetor for internal combustion engines having an air inlet passage, a choke valve assembly in said inlet passage movable to variably regulate the iiow of air through said passage and operating means therefor, said choke valve assembly comprising main and secondary parts, said main part being of such size and so arranged as to substantially close the intake passage' when the valve assembly is in its closed position and to restrict the passage to a greater degree than does the secondary part when the valve assembly is in such position, and said secondary part being of such size and so arranged with respect to the main part that as the valve assembly is moved toward open position the secondary part will occupy an obstructing position nearer the adjacent wall of the intake passage than the main part of the valve assembly so as to control air ow through said passage to a greater degree than the main part of said valve assembly.

15. In a. carburetor for 4internal combustion engines having an air inlet passage, a choke valve assembly in said inlet passage movable to variably regulate the flow of air through said passage and operating means therefor, said choke valve assembly comprising main and secondary parts, said main part being of such size and so arranged as t0 substantially close the intake passage when the valve assembly is in its closed position and to restrict the passage to a greater degree than does the secondary part when the valve assembly is in such position, and said secondary part being relatively movable with respect to the main part oi the valve assembly and also or such a size and so arranged with respect thereto that as the valve assembly is moved toward` its open position the secondary part will occupy an obstructing position nearer the adjacent wall of the intake passage than the main part of the valve assembly so as to control air ilow through said passage to a greater degree than the main part of said valve assembly.

casco 16. In a carburetor for internal combustion engines having an air inlet passage. a choke valve assembly in said inlet passage movable to variably regulate the flow of air through said passage and operating means therefor, said choke valve assembly comprising main and secondary parts, said main part being of such size and so arranged as to substantially close the intake passage when the valve assembly is in its closed position and to restrict the passage to a greater degree than does' the secondary part when the valve assembly is in such position, said secondary part being relative- 1y movable with respect to the main part of said valve assembly, and resilient means connecting the secondary part to the main part, said resilient means being adapted to hold said secondary part in such position with respect to the main part that as the valve assembly is moved toward its open position, the secondary part will occupy an obstructing position nearer the adjacent wall of the intake passage thanthe main part of the valve assembly so as to control air flow through said passage to a greater degree than the main part of said valve assembly.

17. In a carburetor for internal combustion engines having an air inlet passage, a choke valve assembly in said inlet passage movable to variably regulate the ow of air through said passage and operating means therefor, said choke valve assembly comprising a relatively large main part and a smaller secondary part, said main part being of such sizeV and so arranged as to substantially close the intake passage when the valve assembly is in its closed position, and said smaller secondary part being so arranged with respect to the main part of the valve assembly that as the valve assembly is moved toward its open position and the main part of said valve assembly is moved away from the wall of the intake passage, the secondary part of said valve assembly is moved so that the secondary part will occupy an obstructing position nearer the adjacent wall of the intake than the main part of the valve assembly so as to control the air flow through said passage to a greater degree than the mainpart of said valve assembly. 18. In a carburetor having an air intake passage and a mixtureoutlet passage. a choke valve assembly positioned in the air intake passage of said carburetor and eiective to regulate the iiow of sir therethrough, thermally responsive means operable to hold the valve assembly in position to close the intake passage at low temperatures and to hold the valve assembly in its wide open position when the engine reaches its normal operating temperature, suction operated means eiective -to move the valve assembly toward its open position during the warm-up period of the engine. said choke valve assembly including main and secondary parts,` said main part of such size and so arranged as to substantially close the intake and to restrict such passage to a greater degree than does the secondary part when the valve assembly is held in its closed position by the thermally responsive means, and said secondary part being of such size and so larranged with respect to the main part and the wall of the intake passage that as the valve assembly is moved toward open position by engine suction, the secondary part of said valve assembly will be moved to a position where it is nearer the adjacent wall or the intakepassage than the main part and will obstruct the ow of entering air to a greater degree than does the main part or said valve assembly.

19. In a carburetor having an air intake passage and a mixture outlet passage, a choke valve assembly positioned in the air intake passage oi said carburetor and eilective to regulate the flow of air therethrough, thermally responsive means operable to hold the valve assembly in position to close the intake passage at low temperatures and to hold the valve assembly in its wide open position when the engine reaches its normal operating temperature, suction operated means eilective to move the valve assembly toward its open position during the warm-up period of the engine, said choke valve assembly .including main and secondary parts, said main part of such size and so arranged as to substantially close the intake and to restrict such passage to a greater degree than does the secondary part when the valve assembly is held in its closed position by the thermally responsive means, and said secondary part being movable relative to the main part and of such size and so arranged with respect to the main part and the wall of the intake passage that as the valve assembly is moved toward open position by engine suction, the secondary part of said valve assembly willbe moved to a position where it is nearer the adjacent wall of the intake passage than the main part and will obstruct the ilow of entering air to a greater degree than does the main part of said valve assembly.

20. In' a carburetor having an air intake passage and a mixture outlet passage, a choke valve assembly positioned in the air intake passage of said carburetor and effective to regulate the flow of air therethrough, thermally responsive means operable to hold the valve assembly in position to close the intake passage at low temperatures and to hold the valve assembly in its wide open position when the engine reaches its normal operating temperature, suction operated means effective to move the valve .assembly toward its open position during the warm up period of the engine. said choke valve assembly including main and secondary parts, said main part of such size and so arranged as to substantially close the intake and to restrict such passage to a .greater degree than does the secondary part when the valve assembly is held in its closed position by the thermally responsive means, and said secondary part being that the secondary part will be moved to a position where it is nearer the adjacent wall of the intake passage than the main part and will obstruct the ow of entering air to a greater degree than does the main part of said valve assembly.

21. In a carburetor having an air intake passage and a mixture outlet passage, a choke valve assembly positioned in the air intake passage ol" said carburetor and eii'ective to regulate the ilow of air therethrough, thermally responsive means operable to hold the valve assembly in position to close the intake passage at low temperatures and to hold the valve assembly in its wide open p0- sition when the engine reaches its normal operating temperature, suction operated means effective to move the valve assembly toward its open position during the warm-up period or the engine. said choke valve assembly including a relatively large main part and a smaller secondary part.

sasso said mainnartotsuchsineandsoarransedasto substantially close the intake andto restrict such passage to a greater degree than does the secondary part when the valve assembly is held in its closed position by the thermally responsive means, and said secondary part being ot auch size and so arranged with respect to the main part and the wall ot the intake that as the` valve assembly is moved toward open position by engine suction, the secondary part of said valve assembly will be moved to a positionwhere it is nearer the adjacent wall ot the intake pe than the main part and will obstruct the now of entering air to a greater degree than does the main part of said valve assembly.

. CLARENCE H. JORGENBEN.

12 summons crm The following references are of record in the ille of this patent:

UNITED STATES PATENTS 

